Pets seem to prefer sleeping on sofas and other furniture even when they have an equally soft bed on the floor. It is necessary to keep the animals off upholstered furniture, because if this is not done there soon is a dirty hairy spot on the furniture which corresponds to the animal's preferred position thereon. It is much more difficult and expensive to clean the upholstered furniture than wash a dog bed. And it is much more expensive to frequently replace a set of furniture than to keep a dog off his favored position thereon.
It is not simply teaching them not to lie on the sofa. Dogs frequently know they are not supposed to be on the furniture, and accordingly jump off when they hear someone coming. The easiest, and probably the only effective way to keep an animal off the furniture is to cover the furniture with wooden chairs, or other objects so that they cannot lie on the furniture when the room is unoccupied. The problem with covering the furniture is that it is time consuming and inconvenient. What is needed is a lightweight apparatus that can be conveniently and inconspicuously stored, and which can be quickly positioned on the furniture to thereby prevent the animal from lying thereon.